Cholesterol is a lipid (fat) that circulates in the blood and is essential for the functioning of the body's cells. It is produced naturally by the liver and is introduced through the diet. However, too much cholesterol in the blood can have negative health consequences. In cardiology, the values of two types of cholesterol are particularly important: LDL (low-density lipoprotein) and HDL (high-density lipoprotein).

LDL cholesterol is considered 'bad' cholesterol, as it can be deposited on the walls of arteries, causing atherosclerotic plaques to form. These plaques can reduce or block blood flow, increasing the risk of cardiovascular disease such as myocardial infarction and stroke. On the other hand, HDL cholesterol is considered "good" cholesterol, as it helps remove excess cholesterol from the arteries and carries cholesterol back to the liver for processing and elimination.

Triglycerides , another type of lipid, are also important risk factors for atherosclerosis when they are at elevated levels. Atheromatosis leads to plaque in blood vessels, which reduces blood flow and can cause cardiovascular events.

Atherosclerotic markers are those used to assess the risk of atherosclerosis and cardiovascular disease. The main markers include total cholesterol, LDL, HDL and triglycerides. The ratio between these markers (such as the LDL/HDL ratio) helps doctors to assess the risk of cardiovascular disease.